I feel for you, I kind of understand what you are going through and it is not fair. My husband moved out not long ago. At first he admitted he had problems he needs to deal with. No he goes through a bad phase giving me abuse, blaming me and is, again, reluctant to continue therapy.
It is important that you find therapy, too, to offload all the crap he is giving you. Or find a group in addition to this webpage (it's not the same as seeing people but every little helps). Or both. Don't be shy to ask for help, your second baby is on the way- you and your children will need it!